Exploring Thailand’s Expanding Solar Energy Landscape

Country or Region Overview

Country or Region: Thailand

Capital: Bangkok

Total Population: Approximately 70 million (as of 2025)

Geographical Location: Thailand is located in Southeast Asia, bordered by Myanmar, Laos, Cambodia, Malaysia, and the Andaman Sea. Its tropical climate and year-round sunlight make it a prime location for solar energy development.

Solar resource map copyright at 2021 Solargis. Licensed under the Creative Commons Attribution license (CC BY-SA 4.0). This is a solar resource map from Solargis. For a higher resolution map, please visit and download.

Solar Irradiation Data in Thailand

Thailand benefits from strong solar potential due to its tropical climate and proximity to the equator, with an annual average solar irradiation of 4.5 kWh/m²/day to 5.5 kWh/m²/day. The central and northeastern regions, such as the Chao Phraya Basin and Isan plateau, receive the most consistent sunlight, while southern areas see slightly lower levels due to monsoon cloud cover.
Key Solar Irradiation Data:

Annual Solar Irradiation: 5.0 kWh/m²/day on average nationwide
High Irradiation Regions: Central Thailand (e.g., Nakhon Sawan), Northeast (e.g., Ubon Ratchathani), reaching 5.2 to 5.5 kWh/m²/day
Peak Irradiation: Up to 5.5 kWh/m²/day in dry season (November to April)
Thailand’s installed solar capacity exceeded 3.5 GW by 2024, driven by utility-scale projects like the 100 MW Lopburi Solar Farm and rooftop systems in urban areas. The country targets 36% renewable energy by 2037 under its Power Development Plan (PDP), with solar as a major contributor.

If you need to learn more solar power potential in the Thailand, please feel free to contact Solarvance for more details.

Temperature Factors in Thailand

Average Annual Temperature: Thailand has a tropical climate, with average temperatures ranging from 25°C to 35°C (77°F to 95°F) year-round. The hot season (March to May) can reach 40°C (104°F), while cooler northern highlands average 20°C to 30°C (68°F to 86°F).
Impact on Solar Panels: High temperatures slightly reduce panel efficiency due to the temperature coefficient, but abundant sunlight compensates. Cooler northern areas optimize performance.
Recommendation: Solar systems should use heat-tolerant panels (e.g., PERC) with good ventilation for lowland areas, while standard high-efficiency panels suit northern highlands. Durable inverters ensure reliability in humid, warm conditions.

Energy Demand and Grid Situation in Thailand

National Energy Demand: Thailand’s energy consumption is growing with its industrial base, tourism sector, and urban population, totaling over 200 TWh annually. Coal and natural gas dominate (70% of supply), but solar and biomass are rising, with solar contributing 5% by 2024, spurred by high electricity costs and renewable goals.
Grid Infrastructure: The Electricity Generating Authority of Thailand (EGAT) manages a robust grid in urban and industrial zones like Bangkok and Chonburi, but rural areas in the northeast and south face connectivity gaps. The Solar Home System program has electrified over 200,000 rural households, targeting 100% access by 2030.
Opportunities from Global Events: Thailand’s hosting of ASEAN summits, trade expos, and tourism events in Bangkok and Phuket could highlight its renewable progress, driving demand for solar-powered infrastructure in hotels, factories, and public facilities.

Preferred System Type in Thailand

Grid-Connected Systems: Ideal for urban hubs like Bangkok, Chiang Mai, and Pattaya, where grid-tied solar with net metering offsets bills for homes, businesses, and factories under the SPP and VSPP programs.
Off-Grid Systems: Critical for rural villages in Isan and southern islands, off-grid solar with battery storage powers homes, schools, and farms, replacing diesel in remote areas.
Hybrid Systems: For industrial parks, resorts, and small towns, hybrid systems combining solar with biomass or diesel backups ensure reliability during monsoons or peak demand.

Dust and Sand Factor in Thailand

Dust and Sandstorms: Dust is not a significant issue in Thailand due to its tropical, humid climate and dense vegetation. Seasonal haze from agricultural burning in the north (e.g., Chiang Mai) may deposit particles, but it’s minimal compared to desert regions.
Recommendation: Basic cleaning removes occasional haze or pollen buildup. Tilted panels and rainfall naturally manage dust, making advanced dust-mitigation unnecessary.

Humidity and Rainfall (Humidity Factor) in Thailand

Humidity Levels: Humidity is high, averaging 70% to 90%, due to the tropical climate and monsoon influence. Rainfall averages 1,200 to 2,500 mm/year, peaking during the wet season (May to October).
Impact on Solar Panels: High humidity and rain pose a slight risk of moisture ingress, though modern sealing prevents issues. Rainfall cleans panels but reduces output during monsoons.
Recommendation: Panels with robust encapsulation and anti-reflective coatings suit wet conditions. Weatherproof mounting systems ensure durability against heavy rain and occasional floods.

Ocean (Salt Corrosion Factor) in Thailand

Saltwater Corrosion: Thailand’s 3,219 km coastline along the Gulf of Thailand and Andaman Sea exposes coastal areas like Phuket, Krabi, and Pattaya to saltwater corrosion from sea spray and humid winds.
Recommendation: Solar systems should use marine-grade materials and anti-corrosion coatings in coastal regions. Regular cleaning removes salt deposits, ensuring longevity in tourist-heavy areas.

Government Policies and Solar Incentives in Thailand

Thailand’s renewable energy framework supports solar expansion:

Power Development Plan (PDP 2021-2037): Targets 15 GW of solar capacity by 2037, including 2.7 GW of floating solar on reservoirs.
Feed-in Tariffs (FiT): Subsidizes solar projects, with rates for small producers (e.g., 4.5 THB/kWh) encouraging rooftop adoption.
Net Metering and Tax Breaks: Incentives under the Energy Conservation Promotion Act boost residential and commercial solar.
These policies aim to reduce fossil fuel reliance and position Thailand as a renewable energy leader in ASEAN.

ROI on Solar Systems in Thailand

ROI Period: Solar ROI ranges from 4 to 7 years, with urban grid-tied systems achieving payback in 4 to 5 years and rural off-grid setups taking 6 to 7 years, boosted by high electricity rates and diesel savings.
Long-Term Savings: Over a 25-year lifespan, savings reach 60% to 80% on electricity bills, with significant benefits for factories, resorts, and rural communities.

Conclusion on Solar Power in Thailand

Thailand’s strong solar resources, rising energy demand, and supportive policies — like the Alternative Energy Development Plan — create a golden opportunity for solar investment. As the country pushes for 30% renewable energy by 2037, solar energy is becoming a cornerstone of Thailand’s sustainable future.

From city rooftops to rural villages and island resorts, solar power offers energy security, cost savings, and environmental benefits — all while reducing reliance on imported fuels.

Solarvance is equipped to support Thailand’s solar boom, offering reliable, efficient solar solutions designed for tropical climates and coastal areas.

Let’s connect and make solar energy a profitable part of your energy future in Thailand. Solarvance is ready to provide custom solar solutions to support Thailand’s clean energy future.

Choose Solarvance for Your Solar System

Contact us today to explore customized solar solutions for your needs, whether you’re interested in grid-connected, off-grid, or hybrid solar systems. Our team at Solarvance is here to guide you through every step of the process, from system design to installation and maintenance.